1. Field of the Invention
The present invention relates to an imaging dynodes arrangement for an electron multiplier. In particular, it relates to an imaging dynodes arrangement which can be utilized in a single tube scintillation gamma camera.
2. Description of the Prior Art
An imaging dynodes arrangement for an electron multiplier which comprises at least a first and a second imaging dynodes, having dynode cones with a dynode tip and a dynode base, is for example described in the brochure "Nucleonics Data" pages 1-22, issued by Johnston Laboratories, Cockeysville, Md. 21030 under the number JLI-605. As can particularly be seen from page 3 of this brochure, the first and second imaging dynodes are arranged parallel to each other in staggered positions such that the cone tips of the dynode cones of the second imaging dynodes are always in a position beneath the free cavities between neighboring dynode cones of the first imaging dynode. Furthermore, each first and second imaging dynodes are separated from each other by a mesh of guard plates. Such a prior art imaging dynodes arrangement has a considerably non-uniform charge spread and the dynodes have a relatively low gain.